All terrain vehicles (ATV) are known in the art. The typical ATV is an all-season vehicle supported by a pair of rear drive wheels coupled through a transmission to a prime mover. A pair of front steerable wheels, which may or may not be driven, support the forward end of the vehicle. ATVs are substantially smaller than road vehicles and are intended specifically for off-road use. While commonly perceived to be dedicated recreational vehicles, ATV manufacturers have also produced models well-suited as general-purpose utility vehicles. Particularly, these utility ATVs have such features as: higher output engines; four wheel drive; more sophisticated transmissions (including reverse gear); and towing capability.
To capitalize on this versatility, equipment manufacturers have introduced various implements and attachments for use with ATVs. For example, U.S. Pat. No. 5,513,868 issued to Barr, discloses a trailer for use with an ATV. Similarly, U.S. Pat. Nos. 5,088,215 issued to Ciula and 5,615,745 issued to Cross, disclose plow blades for use with ATVs. While effective for their intended purpose, these implements are passive, requiring no power other than the driving force of the vehicle to operate.
In contrast to passive implements are power implements. Generally speaking, power implements are considerably more complex in both construction and operation as compared to passive implements. Power implements include such devices as mowers, rotary sweepers, and snowblowers. While the present invention is applicable to many types of power implements and to many different vehicles, for the sake of brevity it will be described herein in terms of an apparatus for attaching a powered, snow removal implement to an ATV.
Unlike the snow plow, the snowblower uses a powered auger to collect snow and an impeller to discharge it outwardly through a directional discharge chute. For many reasons, the snowblower is generally perceived to be a more effective snow removal device than the plow. One reason for this perception is that the snowblower's ability to move snow is not entirely dependent on the driving force of the vehicle. As such, snow moving capacity is not directly limited by the vehicle's speed or power. Additionally, since the snowblower is not "pushing" the snow, the vehicle frame structure is not required to withstand the large reaction loads inherent with snow plowing equipment. Furthermore, snowblowers are advantageous over plows in that they propel the snow outwardly away from the area being cleared instead of piling it up at the perimeter. This improves visibility beyond the cleared area and reduces the amount of subsequent drifting. For these reasons, snowblowers offer advantages over the conventional snow plow.
While advantageous in these respects, snowblowers and other power implements also introduce a unique set of problems not encountered with passive implements (e.g., plows). One such problem concerns the weight of the power implement. To explain, the snowblower is typically mounted slightly forward from the front of the vehicle. During operation, the snowblower is placed in a first ground-engaging position. During transportation, the snowblower is moved to a second, raised position. To support the snowblower in both the ground-engaging and the raised positions, adequate support structure is required. In addition, the geometry of the implement and its support structure must not result in excessive vehicle instability. The latter issue is complicated by the fact that the snowblower is offset from the vehicle, thereby amplifying the adverse effect of its weight by the offset distance. This can result in a "front-heavy" design which reduces both vehicle stability and rear wheel traction. Thus, snowblowers have been generally limited to use win larger vehicles (e.g., trucks, tractors) that are specifically designed to support such heavy implements.
Another problem with attaching a snowblower to an ATV is that the snowblower requires power (in addition to the driving force of the vehicle) to operate the auger and impeller. In truck or tractor-mounted equipment, this power is usually provided by a prime mover located on the vehicle through an auxiliary power take-off or "PTO" shaft specifically designed to power such auxiliary equipment. Unfortunately, ATVs typically do not include a PTO shaft.
One possible solution to this problem is shown in U.S. Pat. No. 5,479,730 issued to Gogan. Gogan discloses a self-powered snowblower for mounting to a pickup. While this design is acceptable for use with a heavy road vehicle, the addition of the motor serves to increase the snowblower weight, contributing to the offset weight problem (i.e., "front-heavy" design) discussed above.
Thus, while it is perceived that an ATV-mounted snowblower would increase the already broad versatility of this popular vehicle, significant problems remain. Particularly, problems resulting from the offset weight of the implement and lack of an available power source are most prevalent. Thus, an attachment apparatus that can accommodate these needs without adversely affecting ATV performance and stability is highly desirable.